Grinding machine



Jan. 3l, 1967 G. HJYouN-G ETAL 3,300,906

` GRINDING MACHINE Filed Maron 12, 1964 l 5 sheets-sheep 1 n .f Q "l N *gr :l: m

Jan. 31, 1967 0 G. H. YouNG ETAL 3,300,906

GRINDING MACHINE Filed March'lZ, 1964 v 5 Sheets-Sheet 2 Jn. 3l, 1967 G. H. YOUNG E TAL GRINDING MACHINE 3 Sheets-Sheet I5 Filed March l2, 1964 United States Patent Oliiee 3,300,906 Patented Jan. 3l, 1967 3,300,906 GRINDING MACHINE George H. Young, Coatesville, and Richard E. Jones, Natrona Heights, Pa., assignors to Allegheny Ludlum Steel Corporation, Brackenridge, Pa., a corporation of Pennsylvania Filed Mar. 12, 1964, Ser. No. 351,394 16 Claims. (Cl. 51-54) Trhis invention relates to grinding devices, and more particularly to a device for automatically grinding steel plates.

In the normal processing of certain types of stainless steels and other alloy steels, it is necessary to ,grind the surface of the hot rolled plates to remove scabs and the like lto prevent the surface defects from manifesting themselves during subsequent operations and spoiling the iinished surface of the material. This grinding operation is characteristically done by Workmen using electrically driven hand grinders. The surface is first completely ground with these grinders to remove scale, scabs and shallow defects, and then any remaining deep defects which have not lbeen re-moved by the over-all grinding are spot ground to provide a plate, the surface of which is suitable for further processing. This hand grinding operation is an expensive, tithe-consuming process which adds substantially to the processing costs of the steel.

It is therefore a principal object of this invention to provide a device for mechanically grinding the surface of plates.

It is a further object of this invention to provide a device which will automatically grind the entire surface of steel plates.

Still a further object of this invention is to provide a plate grinding device which is adapted to grind a variety of sizes of plates.

rI`hese and other objects, together with a fuller understanding of the invention, may be had with reference to the following description taken in conjunction with lthe drawings in which:

FIGURE 1 is a plan view of the device of this invention;

FIG. 2 is a front elevational view of the device of FIG. 1;

FIG. 3 is a side elevational view of the device of FIG. 1;

FIG. 4 is a sectional view, taken substantially along the plane of line IV-IV, of FIG. 2;

FIG. 5 is a sectional view taken substantially along the plane of line V-V, of FIG. 4;

FIG. 6 is a detailed end elevational view of the lifting cylinder and shaft incorporated in this invention;

FIG. 7 is a detailed end elevational view of the mounting of a grinder incorporated in this invention;

FIG. 8 is a detailed front elevational view of the lifting mechanism for one of the end grinders, and

FIG. 9 is a sectional view taken substantially along the plane of line IX-IX of FIG. 8.

Referring now to the drawings, and particularly to FIGS. l through 3, the device of this invention includes a fabricated steel gantry bridge structure designated generally as 10. The bridge structure 10 includes a center span 12 supported at its opposite ends by a .pair of support towers or legs 14 and 16. The support towers 14 and 16 are provided with tianged wheels 18 which are mounted on tracks 20 so that the bridge structure is movable therealong. The wheels 118 are driven in one direction by a low-speed gear head 4motor 22 and in the other direction by a high-speed return motor 22A. The motors are drivingly connected to the wheels through gears shown schematically at 23, and chain and sprocket system 24.

The bridge structure 10 spans in gantry fashion a workpiece supporting area which is provided with a plurality of skids 26 lupon which the plates to be ground are supported.

The center span 12 of the bridge structure includes an I-beam 28 which supports a pair of tracks 29. A trolley 30 is mounted on the tracks 29 by means of upper flanged wheels 32 and lower guide wheels 32A (see FIG. 5). An air cylinder 33 is mounted on the I-bea-m 28 and its piston rod 33A is connected to the trolley 30 by a bracket 34 which is bolted to the trolley 30 by bolts 34A. The air cylinder 33 is connected to a source of compressed air (not shown) in a conventional manner to drive the piston rod and, hence, the trolley 30 reciprocally on the tracks 29.

A plurality of support brackets 35 are secured to the .underside of the trolley 30 at regular intervals, and wrist pins 36 pivotally ymount grinder support arms 38 to each of the bracket 35.

As can Ibest be seen in FIG. 5, electric grinders 40, each having a conventional grinding wheel 41, are pivotally mounted 'by means of pins 42 to the end of each support arm 38, and each grinder is mounted in such a Way that the grinding head or portion to the left of pin 42 (as seen in FIG. 3) is heavier than the handle portion or portion to the right of the pin 42. The reason for this mounting will be discussed presently. The support arms 38 are adapted to be oscillated in a vertical plane by means of a second air cylinder 44. 'Ilhe air cylinder 44 is trunnion mounted on a bracket 46 which is bolted to the trolley 30 iby bolts 47. Each support arm. 38 is connected by a cable 48 to a pivot arm 50, the pivot arms Ibeing keyed to an oscillating shaft 52, which in turn is journalled by a plurality of support bushings 53 carried by support members 54 bolted to the trolley 30 by bolts 55. The ,pivot arms 50 are connected by connecting links 56 and pin 57 to the air cylinder 44. Thus when the air cylinder `44 is connected in a conventional manner to an air supply (not shown), the reciprocating action of the air cylinder will oscillate the pivot arms 50 in a vertical plane. This, in turn, will oscillate the support arms 38 in a vertical plane through the cables 48.

Each of the support lmembers 54 is provided with a hook 58 depending therefrom which is adapted toengage an eye 60 on the grinder support arms 38. The support arms 38 can therefore be lifted to raise the grinding wheel out of contact with the plate when any particular grinder is not required. A bracket 62 with a U- shaped recess 63 lis provided on the grinder arms 38 to prevent excessive tilting of the grinder 40 when the arm is raised to disengage the grinder from the plate and to impart an oscillating movement to the ginder as will be explained presently.

Referring now to FIGS. 2 and 8, the grinder support arms 3S at opposite ends of the trolley 30 are each provided with a lifting arm 64 adapted to coact with a lbar 66, the underside of which provides a cam surface 68. The lifting arm 64 is pivotally mounted on the trolley 30 by a pin 70 and has a normally horizontal portion 72 and a normally vertical portion '76. The horizontal p0rtion 72 is connected .by a cable 74 to the support arm 38, and the vertical portion 76 has a cam follower wheel 78 at the end thereof. The bar 66 is secured to the I-beam 28 by bolts 80 which extend through elongated slots 82 in the bar 66. This allows the bar to be adjusted longitudinally on the I-beam 28 for a purpose which will become apparent presently.

Operation` In order to grind a plate, the plate is positioned on the skids 26 and the bridge 10 is positioned so that the grinding wheels are located at the front or leading edge of the plate i.e., the lower edge as viewed in FIG. 1. The plate preferably is positioned so that at the extreme limit of movement of the trolley 30 to the left (as seen in FIG. 2), the Contact surface of the grinding wheel 41 of the left end grinder will come just to the lateral left edge ofthe plate. The bar 66 at the right side is adjusted so that the cam follower 78 engages the cam surface 68 justas the grinder on the right side reaches the right lateral edge of the plate. (The bar 66 at the left side is moved to the extreme left so that it does not interfere with the operation. This bar is used only when the right edge of the slab is adjusted to the right side grinder in which case the right side bar is not used.) The grinders are then started, and the air cylinder 33 is actuated. The actuation of the air cylinder 33 will cause the trolley 3i) to reciprocate on the tracks 29, which will reciprocate the grinding wheels on the plate. Simultaneously, the low speed gearhead motor 22 is started to move the bridge structure 10 slowly along the tracks Z upwardly, as seen in FIG. l. Thus, as the grinders are oscillating in one direction, the bridge is moving in ra direction normal to the direction of oscillation of the grinding wheel. It should lbe noted that the distance of oscillation of the trolley must be at least equal to the distance between the grinding surfaces on the grinding lwheels so that the entire surface of the plate will be covered as the trolley oscillates and as the bridge moves. As was indicated previously, the bar -66 is ladjusted so that just as the right-hand grinder reaches the edge of the plate, the cam follower 78 engages the cam surface 68. As can be seen in FIG. 8, as the cam follower 7S follows the cam surface 68, the lifting arm 64 will tend to pivot counterclockwise, which will cause the horizontal portion 72 of the arm 64 to rise, thus raising the support arm 38 by means of the cable 74. This will prevent the right end grinder from falling olf the plate. When the trolley 30 moves back to the left, the -lifting .arm 64 will pivot clockwise under the weight of the support arms 38 to return the grinding wheel to the surface of the plate. The clockwise movement continues until the grinding wheel contacts the surface of the workpiece. During operation, the arms 38 are oscillated in a vertical plane by means of the air cylinder 44. This vertical oscil lation will cause a rocking movement on the grinding wheels about pins 42 due to the balancing of the grinders with the heavier portions to the left of the pin d2. This oscillating or rocking movement will tend to wear the surface of the grinding wheels 41 in a hemispheric pattern (as viewed cross Isectionally), as opposed to a conical pattern. The hemispheric pattern will tend to give .a point Contact during grinding whereas the conical pattern will tend to give line contact, and point contact grinding, as is well known in the art, is much preferred.

Conventional solenoid valves are used to control the oscillation of the air cylinder, this type of valve being Iwell known in the art. The power to drive the bridge 10 and the grinders 40 is supplied from 1any conventional electrical power source and may be supplied, as shown schematically in FIG. 3, through a power track cable S6. (Powertrak is la trademark of Gleason Reel Corp., 798 Horioon Street, Mayville, Wis.)

When the bridge has moved sufficiently to complete the grinding of the plate, the gearhead motor 22 is stopped and the high speed return motor 22A is started to return the lbridge readying it for grinding the next plate.

Although Ione embodiment of this invention has been shown and described, various adaptations and modificattions thereof may be made without departing Ifrom the spirit and scope of the appended claims.

We claim:

1. Apparatus for grinding a flat surface on a` workpiece comprising, workpiece support means adapted to support the workpiece in a grinding position, a grinder support bridge spanning said workpiece support means, a plurality of grinders mounted on said bridge and depending therefrom disposed to grind the surface of said workpiece, means to reciprocate said grinders on said bridge, means for oscillating the grinders t-o control the grinder wear yfor providing point contact Iwith the workpiece, and means to move said bridge and said workpiece support means relatively in ya direction normal to the direction of reciprocation of said grinders.

' 2. Apparatus for grinding a flat surface on a workpiece comprising, workpiece support means adapted to support the workpiece in a grinding position, a grinder support bridge spanning said workpiece support means, said bridge including a frame member and a carriage member mounted for movement on said frame member, a plurality of grinders 4mounted on said carriage member and depending therefrom disposed to grind the surface of the supported workpiece, means to move said carriage member reciprocally on said frame member, means for oscillating the grinders to control the grinder wear for providing point contact with the workpiece and means to move said bridge and said workpiece support means relatively in a direction normal to the direction of re-ciprocation of said grinders.

3. Apparatus for grinding a flat surface on a `workpiece comprising, workpiece support means adapted to support the workpiece in -a grinding position, a grinder support bridge spanning said workpiece support means, said bridge including a frame member and a carriage member mounted Ifor movement on said frame member, a plurality of grinders mounted on said carriage member at regular intervals and depending therefrom disposed to grind the surface of the supported workpiece, means to move said carriage member reciprocally on said frame member a distance equal t-o at least the distance betwen adjacent grinders, and means to move said bridge, means for oscillating the grinders to control the grinder Wear for providing point Contact with the workpiece and said workpiece support means relatively in a direction normal to the direction of recipr-ocation of said grinders.

4. Apparatus vfor grinding a flat surface on a workpiece comprising, workpiece support means adapted to support the workpiece in a grinding position, a grinder support bridge spanning said workpiece support means, said bridge including a frame member and a carriage member mounted for movement on said frame member, a plurality of arms mounted on said carriage member, a grinder mounted on e-ach of said arms, the grinding wheel rotating about an axis generally perpendicular to the fworkpiece, means to move said carriage member reciprocally on said frame member a distance equal to at least the distance between ladjacent grinders, means for oscillating the axes of the grinders to control the pattern of grinder wear, and means to move said bridge Iand said workpiece support means relatively in a direction normal to the direction o-f reciprocation of said grinders.

5. Apparatus for grinding a flat surface on a workpiece comprising7 workpiece support means adapted to support the workpiece in `a grinding position, a grinder support bridge spanning said workpiece support means, said bridge including a frame member and a carriage member mounted for movement on said frame member, a plurality of grinders mounted on said carriage lmember at regular intervals and depending therefrom disposed to grind the surface of the supported workpiece, means to move said carriage member lreciprocally on said -fr-ame member a distance equal to at least the distance between adjacent grinders, `means to ioscillate the grinders during operation to control the pattern of grinder wear, and means to move said bridge 'and said workpiece support means relatively in a direction normal to the direction of reciprocation of said grinders.

6. Apparatus for grinding a flat surface on a workpiece comprising, a workpiece-supporting bed adapted to support the 'workpiece in grinding position, a gantry having a bridge spanning said supporting bed, means mounting said gantry for movement from one end of said bed to the other, said bridge including a frame member and a carriage member mounted on said lframe member for movement in a direction normal to the direction of travel of the gantry, a plurality of regularly spaced arms piv- Otally carried by said carriage member, a grinder pivotally mounted on each of said arms the grinding wheel rotating about an axis generally perpendicular to the workpiece and disposed to engage the surface of the workpiece, means to move said carriage reciprocally on said frame member, means for oscillating the axes of the grinders to control the pattern o-f grinder wear, and means to drive said gantry normal to the direction of reciprocation of said carriage.

7. The apparatus of claim 6, further characterized by means to suppo-rt at least one end grinder after it passes the edge of the plate during reciprocation of the carriage.

8. The device of claim 7, further characterized by said means to support the grinder including cam -following means on said carriage operatively connected to the end arm, and cam track means on said bridge positioned to coact with said cam follower to prevent said arm from dropping when the grinder on said arm reaches the edge of the workpiece.

9. The device of claim 8 Ifurther characterized by means to adjust the position of said cam track means with respect to said cam follower.

10. Apparatus for grinding a at surface on a workpie-ce comprising, a workpiece-supporting bed adapted to support the workpiece in grinding position, a gantry having a bridge spanning said supporting bed, tracks on opposite sides of said bed mounting said gantry for movement from one end of said bed to the other, said bridge including a -frame member and a carriage member mounted on said frame member for movement in a direction normal to the direction of travel of the gantry, a plurality of aligned, regularly spaced arms pivotally carried by said supporting member, a grinder pivotally mounted on each of said arms and disposed to engage the surface of the workpiece, means to move the carriage reciprocally on said frame member, means to oscillate said arms vertically during grinding to control the surface wear patterns, and means to drive said gantry on said tracks.

11. Apparatus for grinding a flat surface on a workpiece comprising, a workpiece-supporting bed adapted to support the workpiece in grinding position, a gantry having a bridge spanning said support bed, tracks on opposite sides of said bed mounting said gantry for movement from one end of said bed to the other, said bridge including a frame member and a carriage member mounted on said frame member for movement in a direction normal to the direction of travel of the gantry, a plurality of aligned, regularly spaced arms pivotally carried by said carriage member, a grinder pivotally mounted on each of said arms and disposed to engage the surface of the workpiece, means to move the carriage reciprocally on said frame member, shaft means interconnecting Isaid arms, means to Eactuate said shaft means to move said arms `in a vertical plane and thereby control the surface wear pattern on the grinders, and means to drive said gantry on ysaid tracks.

12. Apparatus for grinding a at surface on a workpiece comprising, la workpiece-supporting bed adapted to support the workpiece in grinding position, a gantry having a bridge spanning said supporting bed, means mounting said gantry for movement from one end of said bed to the other, said bridge including a frame member and a carriage member mounted on said frame member for movement `in a direction normal to the direction of travel of the gantry, a plurality of aligned, regularly spaced arms pivotally carried by said supporting member, a grinder pivotally mounted on each of said arms, each of said grinders having a grinding wheel rotating about an axis generally perpendicular to the workpiece and disposed to engage the `surface of said workpiece, rst drive means including a fluid actuated cylinder adapted to reciprocate said carriage member on said bridge, the stroke of said cylinder being at least as great as the space between adjacent arms, means for oscillating the -aXes of the grinders to control the pattern of grinder wear and a second drive means including at least one motor adapted to drive said gantry in a direction normal to the direction of reciprocation of said carriage.

13. Apparatus for grinding a at surface on a workpiece comprising, a workpiece-supporting bed adapted to support the workpiece in grinding position,` a `gantry having a bridge spanning said supporting bed, tracks on opposite sides of said bed mounting said gantry for movement from one end of said bed to the other, said bridge including a frame member land a carriage member mounted on said frame member for movement in a direction normal to the direction o-f travel of the gantry, a plurality of aligned, regularly spa-ced arms pivotally carried by said supporting member, a grinder pivotally mounted on e-ach of `said arms, each of said grinders having a -grinding wheel disposed to engage the surface of said workpiece, means to raise and support each of said arms with the grinding wheel of the grinder raised above the surface of the workpiece, first drive means including a fluid actuated cylinder adapted to reciprocate said carriage member on said bridge, the stroke of said cylinder being at least as great as the space between adjacent arms, and a second drive means including at least one m-otor adpated to drive said crane on said tracks.

14. The device of claim 13 further characterized by cam and cam-following means positioned to actuate downward movement of at least one end arm when the grinder thereon passes the edge of the workpiece.

15. Apparatus for grinding a ilat surface on a workpiece comprising, a workpiece-supporting bed adapted to support the workpiece in grinding position, a gantry hav- .ing a bridge spanning said supporting bed, means mounting sa-id gantry for movement from one end of said bed to the other, said bridge including a frame member fand a `carriage member mounted on said frame member for movement in a direction normal to the direction of travel of the gantry, a plurality of regularly spaced arms pivotally carried by said carriage member, `a grinder pivotally mounted on each of said arms and disposed to engage the surface of the workpiece, means to move said carriage reciprocally on said frame member, cam following means on said carriage operatively connected to the Iarm of 'at least one end grinder, cam track means on said bridge positioned to coact with said cam follower to prevent said arm from dropping when the grinder on said arm reaches the edge of the workpiece, and means to drive said gantry normal to the direction of reciprocation of said carriage.

16. The device of claim 15 further characterized by means to adjust the position of said cam track means with respect to said cam follower.

References Cited bythe Examiner UNITED STATES PATENTS 891,197 6/ 1908 Wadsworth 51-56 1,233,120 7/1917 Patch 51-56 1,474,672 11/ 1923 Heuze 5 1 5 6 1,665,776 4/1928 Escole 51-56 1,738,394 12/1929 Saporiti 51-56 1,833,360 11/1931 FOX et al 51-56 1,955,128 4/1934 Henderson 51-56 2,718,732 9/1955 `Cornstock 51-35 X 2,750,714 6/1956 Muehling 51-35 X 3,052,067 9/1962 Dilks 51--35 FOREIGN PATENTS 244,100 7/ 1926 Great Britain.

LESTER M. SWINGLE, Primary Examiner. 

1. APPARATUS FOR GRINDING A FLAT SURFACE ON A WORKPIECE COMPRISING, WORKPIECE SUPPORT MEANS ADAPTED TO SUPPORT THE WORKPIECE IN A GRINDING POSITION, A GRINDER SUPPORT BRIDGE SPANNING SAID WORKPIECE SUPPORT MEANS, A PLURALITY OF GRINDERS MOUNTED ON SAID BRIDGE AND DEPENDING THEREFROM DISPOSED TO GRIND THE SURFACE OF SAID WORKPIECE, MEANS TO RECIPROCATE SAID GRINDERS ON SAID BRIDGE, MEANS FOR OSCILLATING THE GRINDERS TO CONTROL THE GRINDER WEAR FOR PROVIDING POINT CONTACT WITH THE WORKPIECE, AND MEANS TO MOVE SAID BRIDGE AND SAID WORKPIECE SUPPORT MEANS RELATIVELY IN A DIRECTION NORMAL TO THE DIRECTION OF RECIPROCATION OF SAID GRINDERS. 